ASTM_D_7133_-_11.pdf

Designation:D713311Standard Test Method forPolyurethane Raw Materials:Instrumental Measurement ofTristimulus CIELAB Color and Yellowness Index of Liquids1This standard is issued under the fixed designation D7133;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope*1.1 This test method provides an instrumental method formeasuring the CIELAB color and Yellowness Index(YI)ofliquid polyurethane raw materials.The CIELAB and YI resultsare derived from mathematical manipulation of CIE tristimulusvalues in accordance with Practices E308 and E313,respec-tively.1.2 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.NOTE1There is no known ISO equivalent to this standard.2.Referenced Documents2.1 ASTM Standards:2D883 Terminology Relating to PlasticsD1193 Specification for Reagent WaterE180 Practice for Determining the Precision of ASTMMethods for Analysis and Testing of Industrial and Spe-cialty Chemicals(Withdrawn 2009)3E284 Terminology of AppearanceE308 Practice for Computing the Colors of Objects by Usingthe CIE SystemE313 Practice for Calculating Yellowness and WhitenessIndices from Instrumentally Measured Color CoordinatesE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.Terminology3.1 DefinitionsFor definitions of terms that appear in thistest method,refer to Terminologies E284,D883,and theterminology section of Practice E308.4.Summary of Test Method4.1 The color of the total transmitted light is measured by aspectrophotometer in CIE tristimulus values under CIE stan-dard illuminant D65 and CIE 1964 supplementary standardobserver commonly called the 10 standard observer.Thesevalues are then converted by the appropriate equations to theCIELAB color scale and the Yellowness Index.L*a*b*and YIvalues are reported.5.Significance and Use5.1 CIELAB is a visual-based scale that can be used tospecify color and set color tolerances for the polyurethaneindustry.5.2 Yellowness Index specifies the degree of departure ofthe sample from colorless towards yellow.This index is onlysuitable for clear liquids with degrees of saturation in yellow(dominant transmission wavelength in the 570 to 580 nmrange).It can be used to set tolerances for appropriatepolyurethane raw materials.5.3 This test method does not include provisions for mate-rials with fluorescence or visible haze(usually greater than 5%haze).5.4 Before proceeding with this test method,make referenceto the specification of the material being tested.Any testspecimen preparation,conditioning,dimensions,or testingparameters or combination thereof,covered in the materialsspecification shall take precedence over those mentioned in thistest method.If there are no material specifications,then thedefault conditions apply.6.Interferences6.1 This test method is to be used to compare samples onlywhen they are measured under the same conditions.6.1.1 The medium in the cuvette used during standardiza-tion of the instrument will have an effect on the measuredresults.Light mineral oil is recommended,however,distilled1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.22 on Cellular Materials-Plastics and Elastomers.Current edition approved Feb.1,2011.Published February 2011.Originallyapproved in 2005.Last previous edition approved in 2005 as D7133-05.DOI:10.1520/D713311.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 water can be used as a substitute but a note of the substitutionmust be included in any report of the results.6.1.2 The temperature of the sample is also expected toaffect the results obtained.7.Apparatus7.1 InstrumentA hemispherical geometry(integratingsphere)spectrophotometer capable of total transmission(TTRAN)CIE tristimulus measurement through a cuvette.TTRAN includes both the regularly transmitted portion and thediffused portion of the incident light.The instrument must becapable of converting CIE XYZ tristimulus values to theCIELAB color scale as defined in Practice E308 using CIED65 standard illuminant and 10 standard observer.Theinstrument